Mercurial > hg > nginx
view src/event/quic/ngx_event_quic_tokens.c @ 9143:48691bab4474
QUIC: fixed probe-congestion deadlock.
When probe timeout expired while congestion window was exhausted, probe PINGs
could not be sent. As a result, lost packets could not be declared lost and
congestion window could not be freed for new packets. This deadlock
continued until connection idle timeout expiration.
Now PINGs are sent separately from the frame queue without congestion control,
as specified by RFC 9002, Section 7:
An endpoint MUST NOT send a packet if it would cause bytes_in_flight
(see Appendix B.2) to be larger than the congestion window, unless the
packet is sent on a PTO timer expiration (see Section 6.2) or when entering
recovery (see Section 7.3.2).
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Mon, 14 Aug 2023 08:28:30 +0400 |
parents | 77c1418916f7 |
children |
line wrap: on
line source
/* * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> #include <ngx_sha1.h> #include <ngx_event_quic_connection.h> static void ngx_quic_address_hash(struct sockaddr *sockaddr, socklen_t socklen, ngx_uint_t no_port, u_char buf[20]); ngx_int_t ngx_quic_new_sr_token(ngx_connection_t *c, ngx_str_t *cid, u_char *secret, u_char *token) { ngx_str_t tmp; tmp.data = secret; tmp.len = NGX_QUIC_SR_KEY_LEN; if (ngx_quic_derive_key(c->log, "sr_token_key", &tmp, cid, token, NGX_QUIC_SR_TOKEN_LEN) != NGX_OK) { return NGX_ERROR; } ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0, "quic stateless reset token %*xs", (size_t) NGX_QUIC_SR_TOKEN_LEN, token); return NGX_OK; } ngx_int_t ngx_quic_new_token(ngx_log_t *log, struct sockaddr *sockaddr, socklen_t socklen, u_char *key, ngx_str_t *token, ngx_str_t *odcid, time_t exp, ngx_uint_t is_retry) { int len, iv_len; u_char *p, *iv; EVP_CIPHER_CTX *ctx; const EVP_CIPHER *cipher; u_char in[NGX_QUIC_MAX_TOKEN_SIZE]; ngx_quic_address_hash(sockaddr, socklen, !is_retry, in); p = in + 20; p = ngx_cpymem(p, &exp, sizeof(time_t)); *p++ = is_retry ? 1 : 0; if (odcid) { *p++ = odcid->len; p = ngx_cpymem(p, odcid->data, odcid->len); } else { *p++ = 0; } len = p - in; cipher = EVP_aes_256_gcm(); iv_len = NGX_QUIC_AES_256_GCM_IV_LEN; if ((size_t) (iv_len + len + NGX_QUIC_AES_256_GCM_TAG_LEN) > token->len) { ngx_log_error(NGX_LOG_ALERT, log, 0, "quic token buffer is too small"); return NGX_ERROR; } ctx = EVP_CIPHER_CTX_new(); if (ctx == NULL) { return NGX_ERROR; } iv = token->data; if (RAND_bytes(iv, iv_len) <= 0 || !EVP_EncryptInit_ex(ctx, cipher, NULL, key, iv)) { EVP_CIPHER_CTX_free(ctx); return NGX_ERROR; } token->len = iv_len; if (EVP_EncryptUpdate(ctx, token->data + token->len, &len, in, len) != 1) { EVP_CIPHER_CTX_free(ctx); return NGX_ERROR; } token->len += len; if (EVP_EncryptFinal_ex(ctx, token->data + token->len, &len) <= 0) { EVP_CIPHER_CTX_free(ctx); return NGX_ERROR; } token->len += len; if (EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_GET_TAG, NGX_QUIC_AES_256_GCM_TAG_LEN, token->data + token->len) == 0) { EVP_CIPHER_CTX_free(ctx); return NGX_ERROR; } token->len += NGX_QUIC_AES_256_GCM_TAG_LEN; EVP_CIPHER_CTX_free(ctx); #ifdef NGX_QUIC_DEBUG_PACKETS ngx_log_debug2(NGX_LOG_DEBUG_EVENT, log, 0, "quic new token len:%uz %xV", token->len, token); #endif return NGX_OK; } static void ngx_quic_address_hash(struct sockaddr *sockaddr, socklen_t socklen, ngx_uint_t no_port, u_char buf[20]) { size_t len; u_char *data; ngx_sha1_t sha1; struct sockaddr_in *sin; #if (NGX_HAVE_INET6) struct sockaddr_in6 *sin6; #endif len = (size_t) socklen; data = (u_char *) sockaddr; if (no_port) { switch (sockaddr->sa_family) { #if (NGX_HAVE_INET6) case AF_INET6: sin6 = (struct sockaddr_in6 *) sockaddr; len = sizeof(struct in6_addr); data = sin6->sin6_addr.s6_addr; break; #endif case AF_INET: sin = (struct sockaddr_in *) sockaddr; len = sizeof(in_addr_t); data = (u_char *) &sin->sin_addr; break; } } ngx_sha1_init(&sha1); ngx_sha1_update(&sha1, data, len); ngx_sha1_final(buf, &sha1); } ngx_int_t ngx_quic_validate_token(ngx_connection_t *c, u_char *key, ngx_quic_header_t *pkt) { int len, tlen, iv_len; u_char *iv, *p; time_t now, exp; size_t total; ngx_str_t odcid; EVP_CIPHER_CTX *ctx; const EVP_CIPHER *cipher; u_char addr_hash[20]; u_char tdec[NGX_QUIC_MAX_TOKEN_SIZE]; #if NGX_SUPPRESS_WARN ngx_str_null(&odcid); #endif /* Retry token or NEW_TOKEN in a previous connection */ cipher = EVP_aes_256_gcm(); iv = pkt->token.data; iv_len = NGX_QUIC_AES_256_GCM_IV_LEN; /* sanity checks */ if (pkt->token.len < (size_t) iv_len + NGX_QUIC_AES_256_GCM_TAG_LEN) { goto garbage; } if (pkt->token.len > (size_t) iv_len + NGX_QUIC_MAX_TOKEN_SIZE + NGX_QUIC_AES_256_GCM_TAG_LEN) { goto garbage; } ctx = EVP_CIPHER_CTX_new(); if (ctx == NULL) { return NGX_ERROR; } if (!EVP_DecryptInit_ex(ctx, cipher, NULL, key, iv)) { EVP_CIPHER_CTX_free(ctx); return NGX_ERROR; } p = pkt->token.data + iv_len; len = pkt->token.len - iv_len - NGX_QUIC_AES_256_GCM_TAG_LEN; if (EVP_DecryptUpdate(ctx, tdec, &tlen, p, len) != 1) { EVP_CIPHER_CTX_free(ctx); goto garbage; } total = tlen; if (EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_TAG, NGX_QUIC_AES_256_GCM_TAG_LEN, p + len) == 0) { EVP_CIPHER_CTX_free(ctx); goto garbage; } if (EVP_DecryptFinal_ex(ctx, tdec + tlen, &tlen) <= 0) { EVP_CIPHER_CTX_free(ctx); goto garbage; } total += tlen; EVP_CIPHER_CTX_free(ctx); if (total < (20 + sizeof(time_t) + 2)) { goto garbage; } p = tdec + 20; ngx_memcpy(&exp, p, sizeof(time_t)); p += sizeof(time_t); pkt->retried = (*p++ == 1); ngx_quic_address_hash(c->sockaddr, c->socklen, !pkt->retried, addr_hash); if (ngx_memcmp(tdec, addr_hash, 20) != 0) { goto bad_token; } odcid.len = *p++; if (odcid.len) { if (odcid.len > NGX_QUIC_MAX_CID_LEN) { goto bad_token; } if ((size_t)(tdec + total - p) < odcid.len) { goto bad_token; } odcid.data = p; } now = ngx_time(); if (now > exp) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "quic expired token"); return NGX_DECLINED; } if (odcid.len) { pkt->odcid.len = odcid.len; pkt->odcid.data = pkt->odcid_buf; ngx_memcpy(pkt->odcid.data, odcid.data, odcid.len); } else { pkt->odcid = pkt->dcid; } pkt->validated = 1; return NGX_OK; garbage: ngx_log_error(NGX_LOG_INFO, c->log, 0, "quic garbage token"); return NGX_ABORT; bad_token: ngx_log_error(NGX_LOG_INFO, c->log, 0, "quic invalid token"); return NGX_DECLINED; }